On 2013-03-12, SilverTip257 <silvertip257 at gmail.com> wrote: > > I've not had any MegaRAID controllers fail, so I can only say they've been > reliable thus far! I think that this is not a helpful comment for the OP. He wants to know, in the event the controller does fail, can he replace it with a similar-but-possibly-not-identical controller and have it recognize the original RAID containers. Just because you have not seen any failures so far does not mean the OP never will. > You start by failing/removing the drive via mdadm. Then hot remove the > disk from the subsystem (ex: SCSI [0]) and finally physically remove it. > Then work in the opposite direction ... hot add (SCSI [1]), clone the > partition layout from one drive to the new with sfdisk, and finally add the > new disk/partitions to your softraid array with mdadm. > > You must hot remove the disk from the SCSI subsystem or the block device > (ex: /dev/sdc) name is occupied and unavailable for the new disk you put in > the system. I've used the above procedure many times to repair softraid > arrays while keeping systems online. This is basically the same procedure for replacing a failed drive in a hardware RAID array, except that there is no need to worry about drive names (since individual drives don't get assigned a name in the kernel). But the point is that replacing a failed drive is the same amount of on-site work in either scenario, so that should not deter the OP from choosing software RAID. (There may be other factors, such as the aforementioned write cache on many RAID cards.) --keith -- kkeller at wombat.san-francisco.ca.us